For a group registration rate at the conference hotel, you can use this form. The booking is done directly to the hotel by the attendee; hotel contact information is on the form. If this is not a suitable option, you can book any hotel you decide.

Taxi

The best way to reach the hotel is by taxi. From the airport it costs about 20-30 Euro.

Note:
If you use a taxi between Athens Airport and hotels / areas in inner city ring in Athens, fare is flat (38 euros at daytime, 50 euros at night time ), with ALL applicable surcharges included. So, toll cost, luggage fee, VAT, airport charge, meter start are ALL included.
Day time (05:00-24:00) Athens Airport to Athens city: 38 €
Night time (24:00-05:00) Athens Airport to Athens city: 50 €

For hotels out of the inner ring, taxi might be ~ 45 euros during daytime.